An optical sensor device comprising a photoconductor structure having first and second partial members and a coupling surface for coupling the optical sensor device to an opposing counter surface of a pane, particularly a windscreen of a motor vehicle, an optical transmitter coupling a beam of rays into the first partial member, an optical receiver receiving a beam of rays emerging from the second partial member, and a printed circuit board on which the transmitter and the receiver are arranged, is known from EP 0 833 764 B1. In this known device, the printed circuit board is arranged perpendicularly to the windscreen of a motor vehicle. The beam of light which is emitted from the transmitter parallel to the plane of the windscreen is coupled into the windscreen via an input section of a radiation conductor. To do this, the beam of light is initially deflected at a first deflection surface through 90 degrees in a direction parallel to the printed circuit board, before it emerges from the input section and enters into the windscreen via two further deflection surfaces through a coupling surface arranged parallel to the windscreen. After several reflections in the windscreen, the beam of light emerges from the windscreen and is directed onto the receiver on the printed circuit board via an output section formed symmetrically to the input section.
It is an object of the invention to provide an optical sensor device with a simpler and more compact construction which is able to be produced at a more favourable cost.